An fitting fuel line adaptors

[Murt TTA]

I am in the process of turbo ls swap into my 87 GN and I was looking for AN adapters that go from the factory fuel lines at the frame rail to -AN fittings.

Does anyone have a part number for an AN fitting / adaptor to the factory GN fuel line feed and return near the frame rail?

I want to keep the stock fuel lines for now and run -AN lines to the fuel rail.

thanks

 

[The_Six]

stock feed line fitting
female 16mm to AN6 Russell Performance 640830 - Russell AN to Metric Adapter Fittings
Now the return hose line end its tricky the threads are 10mmx1.25 so to get around it you need a weld on steel 6AN fitting you then cut the end off of a stock hose the metal end that screws on to the return fitting and take the original female fitting from the hose and weld it to the AN6 fitting you may also be able to braze it on haven’t tried that myself but I would think it would work. You will need this.
Aeroquip FBM2872 - Aeroquip AN Flare Adapters
Hope this helps you out.​

 

[machinegun]

For the frame lines I wacked the ends off and replaced them with AN to compression fittings. Works like a charm, no soldering brazing or welding. Easy as pie too.

 

[turbofabricator]

Or better yet......cut the end of the stock 1/4" return line and use a 1/4" steel compression fitting with a 1/8" npt female fitting and then screw in a -6am by 1/8" NPT male. Get rid of that saginaw fitting on the return line it is VERY small. I did the same on the supply side to even the fuel filter was removed and added a good aftermarket unit. Not needed for cars running 10.0 or slower, though.

 

[Ttype6]

For the frame lines I wacked the ends off and replaced them with AN to compression fittings. Works like a charm, no soldering brazing or welding. Easy as pie too.

Stop cutting the stock lines. You can drill out the O-ring areas with a .299" drill and the restriction is gone and it still looks stock.

 

[turbofabricator]

The stock return line is a 1/4" line!!!! .299" is larger than the line itself. The stock feed line is a 3/8" line. .299" is a compromise when you can fix it right. Nothing wrong with cutting stock lines. Nothing special. There are better lines available NEW from two suppliers if you ever want to send it back to the dark ages (stock) Removing all the Saginaw fittings from the car will never be seen. They are all under the car or under the AC compressor.

 

[Ttype6]

The stock return line is a 1/4" line!!!! .299" is larger than the line itself. The stock feed line is a 3/8" line. .299" is a compromise when you can fix it right. Nothing wrong with cutting stock lines. Nothing special. There are better lines available NEW from two suppliers if you ever want to send it back to the dark ages (stock) Removing all the Saginaw fittings from the car will never be seen. They are all under the car or under the AC compressor.

I'm not concerned with returning fuel to the tank. I'm only concerned with supplying more fuel to the motor. if the motor needs more fuel and you give it the extra fuel when it is needed,the motor will be using the fuel and there will be no extra amount of fuel to return to the tank. Cutting the lines is easily seen and is unnecessary.Drilling the lines is all that is needed. The dark ages works and so many want to change to something different when it is not needed. There is a good reason why compression fittings are prohibited in many classes of racing.

 

[S10xGN]

I'm not concerned with returning fuel to the tank. I'm only concerned with supplying more fuel to the motor. if the motor needs more fuel and you give it the extra fuel when it is needed,the motor will be using the fuel and there will be no extra amount of fuel to return to the tank. Cutting the lines is easily seen and is unnecessary.Drilling the lines is all that is needed. The dark ages works and so many want to change to something different when it is not needed. There is a good reason why compression fittings are prohibited in many classes of racing.

You should be concerned, as these pump puts out "X" amount of fuel continuously. What happens to all that fuel when the demand is low ? ? ?

 

[turbofabricator]

I'm not concerned with returning fuel to the tank. I'm only concerned with supplying more fuel to the motor. if the motor needs more fuel and you give it the extra fuel when it is needed,the motor will be using the fuel and there will be no extra amount of fuel to return to the tank. Cutting the lines is easily seen and is unnecessary.Drilling the lines is all that is needed. The dark ages works and so many want to change to something different when it is not needed. There is a good reason why compression fittings are prohibited in many classes of racing.

Ummmm...OK. I have never seen a tech article that bans compression fittings. (but there just might be one somewhere) I have been building everyting from 5,000+ HP Unlimited Hydroplanes, to SCCA race cars, NASCAR, to Pikes Peak hill climb cars, to NHRA drag cars for over 30 years and never heard anything about compression fittings (there are good fittings and low quality fittings, though). As a matter of fact, I use hydraulic compression fittings on 5,000psi hydraulic fittings on Commercial aircraft. I am personally certified in "axial swedge" hydraulic fittings for both aluminum and titainium hydraulic systems. Speaking of dark ages............... . If I make a mistake 200-500+ people lose their lives. Not something I take lightly, EVER!!!! We even test our compression fittings with high pressure helium because helium molecules are smaller than compressed air (and synthetic hydraulic fluid used on aircraft-Skydrol) and is easy to detect with a meter. There are hundreds of compression fittings on the new 787 airplane. (and current fighter jets)

If you do not provide a return path for copious amount of fuel you will get pressure creep and poor pressure control. Check some of my posts on how we increased the cross sectional area of both the feed and the return path. I have even used brass compression fittings on my own car 20 years ago and they never leaked. Now I only use steel or stainless steel compression fitings which are rated for 3,000 psi. I'm SURE they will work fine with 70 psi max. If you would like more info on steel/stainless compression fittings, look into "Swagelock". Heck, the factory all now use PLASTIC fittings with EFI???

 

[Pronto]

For the frame lines I wacked the ends off and replaced them with AN to compression fittings. Works like a charm, no soldering brazing or welding. Easy as pie too.

What did you do for the fuel filter? That area seems tight to fit an aftermarket filter in.

 

[Ttype6]

Ummmm...OK. I have never seen a tech article that bans compression fittings. (but there just might be one somewhere) I have been building everyting from 5,000+ HP Unlimited Hydroplanes, to SCCA race cars, NASCAR, to Pikes Peak hill climb cars, to NHRA drag cars for over 30 years and never heard anything about compression fittings (there are good fittings and low quality fittings, though). As a matter of fact, I use hydraulic compression fittings on 5,000psi hydraulic fittings on Commercial aircraft. I am personally certified in "axial swedge" hydraulic fittings for both aluminum and titainium hydraulic systems. Speaking of dark ages............... . If I make a mistake 200-500+ people lose their lives. Not something I take lightly, EVER!!!! We even test our compression fittings with high pressure helium because helium molecules are smaller than compressed air (and synthetic hydraulic fluid used on aircraft-Skydrol) and is easy to detect with a meter. There are hundreds of compression fittings on the new 787 airplane. (and current fighter jets)

If you do not provide a return path for copious amount of fuel you will get pressure creep and poor pressure control. Check some of my posts on how we increased the cross sectional area of both the feed and the return path. I have even used brass compression fittings on my own car 20 years ago and they never leaked. Now I only use steel or stainless steel compression fitings which are rated for 3,000 psi. I'm SURE they will work fine with 70 psi max. If you would like more info on steel/stainless compression fittings, look into "Swagelock". Heck, the factory all now use PLASTIC fittings with EFI???

Again,people are cutting the lines when there is no need. Again,if you increase the supply volume to a much greater amount than the motor needs at any given time ,the return line becomes a restriction. Give the motor what it needs when it needs it and you will be returning very little fuel to the tank and the return line diameter wont need to be increased.

 

[Ttype6]

You should be concerned, as these pump puts out "X" amount of fuel continuously. What happens to all that fuel when the demand is low ? ? ?

Why do you send so much fuel to the motor when it's not needed. Doing this is what makes the return line a restriction. Send only a little more fuel to the motor than is needed at any given time and the return line won't become a restriction and the fuel won't get heated needlessly.

 

[Pronto]

Seems to me Ken's solution is simple and inexpensive and worth it. The increased volume of fuel isn't like going to AN 10 lines, shouldn't cause any issues.

 

[S10xGN]

Why do you send so much fuel to the motor when it's not needed. Doing this is what makes the return line a restriction. Send only a little more fuel to the motor than is needed at any given time and the return line won't become a restriction and the fuel won't get heated needlessly.

Dude, you really need to get educated on how a fuel pump works...

 

[turbofabricator]

What did you do for the fuel filter? That area seems tight to fit an aftermarket filter in.

I installed a BG filter in the engine bay. Look here: http://turbobuick.com/forums/threads/it-finally-runs.350143/

 

[Ttype6]

Seems to me Ken's solution is simple and inexpensive and worth it. The increased volume of fuel isn't like going to AN 10 lines, shouldn't cause any issues.

Drilling the lines at the Saginaw fittings requires the purchase of one drill and accomplishes the same thing. Why not drill and have stock appearing lines. It's nice when we can play and not butcher a very valuable player in the history of the automobile. Increasing the diameter of the Saginaw fittings to the size of the rest of the supply line by drilling or by cutting and installing compression fittings isn't going to increase volume at low engine speeds. A larger volume pump is the cause of that. Again,I'm only concerned about mutilating a stock part,in the name of relieving a restriction,when it can be accomplished in a way that no visual inspection can detect.

 

[Ttype6]

Dude, you really need to get educated on how a fuel pump works...

I have two. They run on direct current electricity and there flow is directly related to volts.

 

[turbofabricator]

Drilling the lines at the Saginaw fittings requires the purchase of one drill and accomplishes the same thing. Why not drill and have stock appearing lines. It's nice when we can play and not butcher a very valuable player in the history of the automobile. Increasing the diameter of the Saginaw fittings to the size of the rest of the supply line by drilling or by cutting and installing compression fittings isn't going to increase volume at low engine speeds. A larger volume pump is the cause of that. Again,I'm only concerned about mutilating a stock part,in the name of relieving a restriction,when it can be accomplished in a way that no visual inspection can detect.

There is NO way drilling a return line will get it from .098" to .250" ID. Sorry. I've been working on these cars for more than 23 years and there are just some things that CANNOT be accomplished. If you increase the volume at low speed, you MUST have the ability to bleed off the un-needed volume. With BIG pumps(s) they quickly over power the stock 1/4" saginaw fitting at the front frame rail interface. Take it apart some day and you will see what I am talking about. It's not just "Pi x Radius Squared" to calculate the cross sectional gain by removing the saginaw fitting.
Drilling out the Saginaw fittings to meet the ID of the tube itself will completely eliminate the O-ring interface. Now you will have a leak point. But, hey........if your car doesn't need a ton of fuel, you can drill it a bit larger. We are making over 750 HP and we needed to ensure that fuel volume was being met. This is a street car on pump gas/alcohol. Read my other posts on how/why we did what we did to the stock system. If your car runs 10.20's or slower then the stock fuel lines are more than adaquate as is. If drilling out your fuel lines works for you, keep doing it. At 10.0's @ 136+ And everything else that doesn't look stock, (StageII on-center block, turbo, down pipe, Champion intake, Precision SLIC, braided line, valve covers, intake tube, airfilter, MAF, headers, roll bar, 3 muffler exhaust, ...............) we really don't care if the fuel lines aren't stock appearing. AND as stated before...NEW fuel lines are available from at least two aftermarket sources if the owner ever wants to go back to completely stock. Off my soap box.

 

[Ttype6]

There is NO way drilling a return line will get it from .098" to .250" ID. Sorry.

I'll say it again. I'm not talking about the return line. The trend I've been seeing is for people to buy the newest,higher volume single pumps. Going this route moves so much more fuel that the regulator and/or return line can't return all the unused fuel back to the tank,during low engine demands such as idle and off idle. When someone is advised to do this and they turn the advise into action they unknowingly create a problem. Now they have to purchase a regulator that can bypass a greater volume of fuel and/or replace the return line with a larger diameter line. There is no need to modify/replace the return line. The method you're using to supply fuel to your motor is creating the problem. You're sending too much fuel to the motor when it is not needed. However,let me make it very clear that I believe you have every right to do it which ever way you want. My concern is for the people who take this advice when there is a better way to accomplish there fuel supply needs,especially if the car is mostly street driven.
The biggest problem is heating the fuel unnecessarily.

 

[Ttype6]

We are making over 750 HP and we needed to ensure that fuel volume was being met. This is a street car on pump gas/alcohol.

I couldn't agree with you more. Send more fuel to the motor when it's needed and not before.

Generally speaking,there are three methods of fueling our turbo Buicks.

1.Gasoline/Alcohol
2.Gasoline
3. E85

The first method puts the least demand on the fuel system.This is the method you are using.

The third method puts the most demand on the fuel system. This is the method I am using.
I use the Stock Unmodified Return Line
My feed line is stock appearing because I drilled the Saginaw fittings to a larger diameter.
My motor makes 700-750 HP on E85.
I have to move a significantly greater amount of fuel than you do for me to do what I'm doing.
45 lbs of fuel pressure at an idle (line off),71 lbs of fuel pressure at 26 lbs of boost.
Why is my fuel pressure so low at an idle with the stock unmodified return line?
Because I only send a little more fuel to the motor,at any given time,than it needs.

My reason for replying to this thread is to stop the next guy from installing a pump that is too large and needlessly replacing or cutting his stock lines.

The factory lines can take these cars much farther than people think.